Dynamics and Directional Stability of High-Speed Unmanned Aerial Vehicle Ground Taxiing Process

2020 ◽  
Vol 57 (4) ◽  
pp. 689-701
Author(s):  
Qiaozhi Yin ◽  
Hong Nie ◽  
Xiaohui Wei
Author(s):  
Amirhossein Fereidountabar ◽  
Gian Carlo Cardarilli ◽  
Luca Di Nunzio ◽  
Rocco Fazzolari

2017 ◽  
Vol 14 (1) ◽  
pp. 172988141667814 ◽  
Author(s):  
Chao Chen ◽  
Jiyang Zhang ◽  
Daibing Zhang ◽  
Lincheng Shen

Tilt-rotor unmanned aerial vehicles have attracted increasing attention due to their ability to perform vertical take-off and landing and their high-speed cruising abilities, thereby presenting broad application prospects. Considering portability and applications in tasks characterized by constrained or small scope areas, this article presents a compact tricopter configuration tilt-rotor unmanned aerial vehicle with full modes of flight from the rotor mode to the fixed-wing mode and vice versa. The unique multiple modes make the tilt-rotor unmanned aerial vehicle a multi-input multi-output, non-affine, multi-channel cross coupling, and nonlinear system. Considering these characteristics, a control allocation method is designed to make the controller adaptive to the full modes of flight. To reduce the cost, the accurate dynamic model of the tilt-rotor unmanned aerial vehicle is not obtained, so a full-mode flight strategy is designed in view of this situation. An autonomous flight test was conducted, and the results indicate the satisfactory performance of the control allocation method and flight strategy.


Author(s):  
Gian Carlo Cardarilli ◽  
Rocco Fazzolari ◽  
Luca Di Nunzio ◽  
Amirhossein Fereidountabar

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 43
Author(s):  
Xianglei Liu ◽  
Tongxin Guo ◽  
Pengfei Zhang ◽  
Zhenkai Jia ◽  
Xiaohua Tong

To optically capture and analyze the structure and changes of the flow field of a weak airflow object with high accuracy, this study proposes novel weak flow field extraction methods based on background-oriented schlieren. First, a fine background pattern texture and a sensor network layout were designed to satisfy the requirement of weak flow field extraction. Second, the image displacement was extracted by calculating the correlation matrix in the frequency domain for a particle image velocimetry algorithm, and further calculations were performed for the density field using Poisson’s equation. Finally, the time series baseline stacking method was proposed to obtain the flow field changes of weak airflow structures. A combustion experiment was conducted to validate the feasibility and accuracy of the proposed method. The results of a quad-rotor unmanned aerial vehicle experiment showed that the clear, uneven, and continuous quantitative laminar flow field could be obtained directly, which overcame the interference of the weak airflow, large field of view, and asymmetrical steady flow.


2020 ◽  
Vol 12 (17) ◽  
pp. 2801
Author(s):  
Thomas Bamford ◽  
Filip Medinac ◽  
Kamran Esmaeili

The current techniques used for monitoring the blasting process in open pit mines are manual, intermittent and inefficient and can expose technical manpower to hazardous conditions. This study presents the application of unmanned aerial vehicle (UAV) systems for monitoring and improving the blasting process in open pit mines. Field experiments were conducted in different open pit mines to assess rock fragmentation, blast-induced damage on final pit walls, blast dynamics and the accuracy of blastholes including production and pre-split holes. The UAV-based monitoring was done in three different stages, including pre-blasting, blasting and post-blasting. In the pre-blasting stage, pit walls were mapped to collect structural data to predict in situ block size distribution and to develop as-built pit wall digital elevation models (DEM) to assess blast-induced damage. This was followed by mapping the production blasthole patterns implemented in the mine to investigate drillhole alignment. To monitor the blasting process, a high-speed camera was mounted on the UAV to investigate blast initiation, sequencing, misfired holes and stemming ejection. In the post-blast stage, the blasted rock pile (muck pile) was monitored to estimate fragmentation and assess muck pile configuration, heave and throw. The collected aerial data provide detailed information and high spatial and temporal resolution on the quality of the blasting process and significant opportunities for process improvement. The current challenges with regards to the application of UAVs for blasting process monitoring are discussed, and recommendations for obtaining the most value out of an UAV application are provided.


2013 ◽  
Vol 401-403 ◽  
pp. 1728-1733
Author(s):  
San Min Shen ◽  
Jing Cui ◽  
Wen Yi Liu

In the environment of harsh weather or obstacles, the corresponding monitoring department can't achieve remote control and acquire the accurate location of the unmanned aerial vehicle (UAV). According to the existing problem this paper designs a logical control module based on single chip microcomputer (SCM) C8051F040 and UAV real-time tracking system which is positioned by GPS. In this design, through the analysis and extraction of the GPS data, then transmit these data to the host computer through the USB interface with high speed, the unmanned aerial vehicle (UAV) flight vector position such as longitude and altitude information will be displayed by the host computer. After tested for several times, this vector pursuit system can acquire the accurate position of the unmanned aerial vehicle (UAV) and the corresponding flight path within 20 km. To some extent, it provides an effective guarantee for the remote control and monitoring department.


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